1. Field of the Invention
The invention relates to batch processing and more particularly, to a method for monitoring sequencing of a control recipe for a batch process, where the recipe comprises recipe elements and is displayable on a display unit of an operator or batch system. In addition, the invention relates to an arrangement having an operator and a batch system that is configured to implement the method.
2. Description of the Related Art
A conventional computer program for implementing a method for monitoring the sequence of a control recipe for a batch process that is displayable on a display unit of an operator or a batch system is disclosed in Siemens catalog “ST PCS 7—March 2010”, SIMATIC PCS 7, chapter 10. As disclosed therein, a user graphically creates a recipe for controlling a batch process on the display unit using “BATCH Software” that can be executed on a programming unit. During a control operation, during which the recipe is sequentially processed by a batch system, where an automation unit that is connected to the batch system online correspondingly respectively processes, for each recipe phase, a functional module assigned to this recipe phase, an operator monitors the recipe sequence using an operator system. For this purpose, the operator follows and monitors the recipe that is graphically displayed on a display unit of the operator system to detect disturbances and problems while controlling the batch process, where individual recipe elements are indicated using particular states. Generally, these particular states do not indicate potential problems but rather indicate—if anything—only specific faults or disturbances reported to the operator system by the hardware of the automation unit. In order to detect possible problems in the overall sequence, such as failure of a loop in the recipe sequence to end because particular characteristic variables are not reached, the operator must always have an overview of the entire recipe. If the control recipes are complex and are also nested, then it is increasingly difficult to continuously follow the sequence.
In addition, a recipe sequence often has recipe elements that require intervention by the operator. Such an intervention, such as selecting a subsystem, a breakpoint acknowledgement or a dialog confirmation, can only be directly performed by the operator within a complete overview of the recipe by a corresponding operation on the recipe element. If a plurality of events requiring operator intervention occur at the same time, the operator quickly loses the overview of the recipe sequence. Furthermore, the operator can overlook required operator intervention, which may result in disturbances in control operation over a relatively long period of time.